United States · Montana · Deer Lodge
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Photo by Tanankyo via Wikimedia Commons (Public domain)
Photo by Tanankyo via Wikimedia Commons (Public domain)
Montana State Prison is a state prison located in Powell County, Montana. Rated capacity: 1,495. Reported population: 1,550. Security level: Maximum. Data sourced from the HIFLD Prison Boundaries open dataset.
The Montana State Prison is an American men's correctional facility of the Montana Department of Corrections in unincorporated Powell County, Montana, about 3.5 miles (5.6 km) west of Deer Lodge. The current facility was constructed between 1974 and 1979 in response to the continued degeneration of the original facility located in downtown Deer Lodge. The "Old Prison" (46°23â²33â³N 112°44â²10â³W) served as the Montana Territorial Prison from its creation in 1871 until Montana achieved statehood in 1889, then continued as the primary penal institution for the State of Montana until 1979. Throughout the prison's history, the institution was plagued with constant overcrowding, insufficient funds, and antiquated facilities. The administration of Warden Frank Conley from 1890 to 1921 proved the exception to this rule, as Warden Conley instituted extensive inmate labor projects that kept many inmates at work constructing the prison buildings and walls as well as providing various state and community services like road building, logging, and ranching.
Source: Wikipedia article lead, CC-BY-SA.
Capacity
1,495
Current population
1,550
Occupancy
104%
Year opened
1886
Operational
Figures from official sources · verified 2 Jun 2026 · methodology
Population held
Mixed/unknown
Opened
1886
Region
Montana
Security level
Maximum
Death-row facility
No
No conditions summary available yet.
No visiting information available.
No mailing information available.
Contact the operator's website for inmate-specific procedures.
No major issues documented in our database.
Derived signal — not a judgement. How it's calculated
What the score is responding to:
This facility scores 5. The national average across 7,437 scored United States facilities is 2 — 3 points above national average.
Same country, matched on type + security level where possible.
How many of our profile fields are populated. We surface this so families and researchers know the limits.
Under CC-BY-4.0. Include the URL and access date; the site is a living reference and entries can change.
World Prisons. (2026). Montana State Prison. Retrieved July 21, 2026, from https://worldprisons.com/prisons/montana-state-prison
"Montana State Prison." World Prisons. Accessed July 21, 2026. https://worldprisons.com/prisons/montana-state-prison.
@misc{worldprisons-montana-state-prison,
author = {{World Prisons}},
title = {Montana State Prison},
year = {2026},
url = {https://worldprisons.com/prisons/montana-state-prison},
urldate = {2026-07-21}
}